Joe,
I respect your opinions, but I most emphatically do not agree with them.
45 years od experience with an Oehler chronograph, maximum loads, and never a problem tells me that the "old" methods worked quite well. And the bigger outfits like Lyman, Sierra, Speer etc did indeed have "crushers" and pressure guns.
cheygriz I don`t doubt you have never had a problem with the old methods. I too have been stuffing powder in cases since the mid 60`s and can only say I`ve had 1 problem with a load using primers, case expansion, extraction, etc as a guide. That one resulted in a stuck case in a 45LC Ruger Blackhawk that also locked up the cylinder due to the case head being jammed back tight against the rear of the action. No damage was done though, and pulling the remaining bullets never reveled the cause. The load was near, but not at book max.
I`ve heard that pressures need to be around 70K PSI piezo for primers to show cratering and flatten excessively. This is 5K psi more then the hottest rifle loads as set by SAAMI. Primers that don`t flatten at 35K psi in your safe and 44 mag load can`t be expected to show problems at 25-30K psi overloads in your 45acp or 44 spcl. Todays newer cartridge styles like the 223/308 or WSM`s with their straighter walled brass doesn`t stick bolts like the old tapered ones did either.
The case is the weakest link in the system and as long as it holds we think we are within safe SAAMI specs. We may be on safe ground as far as the case not rupturing, but we are not always within SAAMI specs. Thankfully the modern firearms and brass is better then it needs to be, and we get away with it.
A bit of info though that you might find interesting on how manuals arrive at their data,
The Speer#10 manual on pg 107 states,
"Over 20 pressure test barrels were added for this #10 manual, and
much of the data is now computer processed ( anyone think "Quick load"?). Over 35,000 rounds were loaded, fired,
and measured in some way for the revisions and additions to the loading data.
Then further on pg 108;
"Where pressure barrels were not available - all of the wildcat and foreign cartridges, and some of the older less popular standard US cartridges- loading data was developed using the primer- appearance/case-extraction-head expansion methods."
This manual was published in 1979 and they were just moving to "pressure barrels and computer models for their data, or so it sounds.
The Hornady 5th edition published in 2000 on pg 70 states "When possible, loading data was fired in a special firearm designed to measure pressure. There is a description of a pressure gun in the Illustrated Glossary" (the glossary shows a crusher gun not the modern strain system)
The newest, just out this month, Hornady 8th edition on pg 78 seems to say Hornady is still in the process of moving to the latest test equipment.
"In some calibers and for some cartridges, pressure barrels were not available. We developed and tested loads in these situations by employing a factory or custom firearm and examining the brass case and the fired case extracted from the chamber. The brass case will show several indications of increasing pressures. One is case head expansion as measured by a good micrometer and compared to a fired, factory loaded cartridge. Other pressure signs of significance were cratered or flattened primers, brass flow into ejector slots, case head expansion, as well as difficult case extraction.
We employed the procedures above only when we had no other options. The vast majority of the data in this book was derived from the use of strain gauges"
Hornady by their own mouth is still using the old methods in some instances
I`ve heard it repeated by too many writers and industry people that todays data changes are due to improved pressure measuring and not lawyers. I can`t believe they all are lying.
Old data was developed by Crusher and the pressures were listed in CUP or LUP depending on the cartridge. later they tried saying CUP was the same as PSI and simply started changing the CUP label to psi. Today we know the difference and PSI is used where it is relevant, with strain measurements, and old crusher data is still listed in most cases as CUP, or no pressure is given for the load. Hodgdons web site is a good place to see this.
Compare a couple different manuals, all modern with data listed for the same bullet and powder. I think you`ll find the velocity of each load falls with in what can be expected to be the extreme spread of the load in most cases, no matter what the powder charge is. they all load to max and all get similar results with the same components
There are a few cartridges out there though, that SAAMI dropped the max pressures slightly on over the years due to spikes or other perceived problems with the higher psi level. The 7mm Rem mag, and 44 mag, are two of them. I think the 357 mag is another. These I can agree are lower due to legal or manufacturing problems of some type. They are not the reason for most of the lowed charges though, and the change and reasoning was published when they happened in a few magazines.